TY - JOUR
T1 - Interface between Sr2RuO4 and Ru-metal inclusion
T2 - Implications for its superconductivity
AU - Ghosh, Soham S.
AU - Xin, Yan
AU - Mao, Zhiqiang
AU - Manousakis, Efstratios
N1 - Funding Information:
This work was supported in part by the U.S. National High Magnetic Field Laboratory, which is partially funded by NSF Grant No. DMR-1157490 and the state of Florida.
Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/11/8
Y1 - 2017/11/8
N2 - Under various conditions of the growth process, when the presumably unconventional superconductor Sr2RuO4 (SRO) contains microinclusions of Ru metal, the superconducting critical temperature increases significantly. An atomic resolution high-angle annular-dark-field scanning transmission electron microscopy study shows a sharp interface geometry which allows crystals of SRO and of Ru metal to grow side by side by forming a commensurate superlattice structure at the interface. In an attempt to shed light on why this happens, we investigated the atomic structure and electronic properties of the interface between the oxide and the metal microinclusions using density functional theory calculations. Our results support the observed structure, indicating that it is energetically favored over other types of Ru-metal/SRO interfaces. We find that t2g-eg orbital mixing occurs at the interface with significantly enhanced magnetic moments. Based on our findings, we argue that an inclusion-mediated interlayer coupling reduces phase fluctuations of the superconducting order parameter, which could explain the observed enhancement of the superconducting critical temperature in SRO samples containing microinclusions.
AB - Under various conditions of the growth process, when the presumably unconventional superconductor Sr2RuO4 (SRO) contains microinclusions of Ru metal, the superconducting critical temperature increases significantly. An atomic resolution high-angle annular-dark-field scanning transmission electron microscopy study shows a sharp interface geometry which allows crystals of SRO and of Ru metal to grow side by side by forming a commensurate superlattice structure at the interface. In an attempt to shed light on why this happens, we investigated the atomic structure and electronic properties of the interface between the oxide and the metal microinclusions using density functional theory calculations. Our results support the observed structure, indicating that it is energetically favored over other types of Ru-metal/SRO interfaces. We find that t2g-eg orbital mixing occurs at the interface with significantly enhanced magnetic moments. Based on our findings, we argue that an inclusion-mediated interlayer coupling reduces phase fluctuations of the superconducting order parameter, which could explain the observed enhancement of the superconducting critical temperature in SRO samples containing microinclusions.
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U2 - 10.1103/PhysRevB.96.184506
DO - 10.1103/PhysRevB.96.184506
M3 - Article
AN - SCOPUS:85038828874
SN - 2469-9950
VL - 96
JO - Physical Review B
JF - Physical Review B
IS - 18
M1 - 184506
ER -